1. Field of the Invention
This invention relates to physical conditioning and medical rehabilitation, general exercise and the toning of the lower extremities of the body. More particularly the invention provides an apparatus and method for maintaining circulation and muscle tone in the feet and lower legs of individuals, which is useful while they are seated or confined to a chair.
2. Prior Art
Vigorous athletes, such as runners and the like, frequently injure their lower legs and/or feet necessitating relatively severe restriction of movement during healing. For example, runners are frequently subject to hairline stress fractures of the bones of the lower leg, also known as "shin splints". Cramps of the calf muscles are also quite common among runners. These types of injuries can often pull or tear muscle tissue, requiring long term enforced inactivity to allow healing to occur. During such enforced inactivity, much of which may be passed resting or reclining in a chair, athletes who are normally quite physically active become uncomfortable or even nervous from lack of exercise. Enforced inactivity also tends to delay healing of the injured muscle tissue. Often, the enforced inactivity will require the injured athlete to spend an inordinate amount of time reclining or sitting in a chair, even while undertaking other activities. While sitting, circulation is often seriously decreased to the lower extremities (legs, ankles, feet, etc.) tending to induce additional injury. These same problems are often encountered by non-athletes, and can be particularly troublesome for older persons, whose level of physical activity may already be diminished and whose physical health may be declining with age.
Physical inactivity often causes the muscular tissue of the heart to lose tone and become weaker. This loss of heart muscle may take place at the same time as extra strain is placed on the heart due to illness or age. Such extra strain can also be due to lack of movement of the muscles. Movement of the muscles of the lower extremities in particular, where many of the major muscles and blood vessels of the body are located, serves normally to significantly aid in pumping blood through the body due, in part, to kneading, or continuing variable pressure, of the moving muscles against adjacent blood vessels. It is frequently estimated that in active walking or running, a significant percentage of the actual pumping of blood in the body, up to as much as twenty to twenty-five percent or more, is due to the pumping effects of blood moving through the vessels of the legs under the impetus of muscles squeezing against blood vessels. Thus, a certain amount of movement of the lower extremities can be very important in maintaining health even in fairly vigorous persons. Consequently, there is a need for a practical exercise apparatus to enable movement in the lower extremities to be continued, at least on a reduced scale, by those persons subjected to long periods of inactivity, particularly in a seated position.
In recent years there have been numerous attempts to provide ergonomically designed office machines and office furniture for improving circulation. These efforts have been directed more toward developing office machines that are less tiring to operate, than providing ways to actually relax the body and maintain circulation by mild exercise. A number of large and small scale exercise machines are known for exercising the legs, such as treadmills, bicycling machines and so-called stepping machines. These and other known exercise apparatus often rely upon a stepping or placing of the weight alternately upon first one leg and then the other while in a standing position, or, at a minimum, while being in a cycling position such as in the use of a stationary bicycle. These types of known exercise machines are normally not devised for use by persons who are seated in a conventional chair, e.g., a desk chair or easy chair. Some examples of known, small scale exercise machines are set forth below.
U.S. Pat. No. 5,256,118--Chen discloses a small scale so-called "stepper" device car pedal exerciser in which two adjacent pedals are pivoted at one end and act against a pair of air bellows between the pedals and a base. The bellows allow the pedals to rise and fall resiliently as the user transfers his or her weight alternatively from one to the other pedal. The device does not appear to be suitable for operation or use from a sitting position.
U.S. Pat. No. 5,267,923--Piaget et al. discloses a stepper-type exercise machine involving the use of bellows at the opposite end of pedals in a small scale, easily portable and storable exercise machine. While the arrangement of the pedals of the Piaget machine is such that it could possibly be used from a seated position, such use would be quite awkward unless the seating was in a position similar to that assumed on a bicycle.
U.S. Pat. No. 5,290,204--Lee discloses a small and compact pedaling machine in which the pedals are pivoted at one end and movement is resisted by a fluid cylinder means of a suitable type and including a coordinating arm to allow only one pedal to be depressed at a time.
U.S. Pat. No. 5,304,105--Hsieh discloses a small scale stepping-type exerciser in which the pedals are pivoted at one end, and are rendered resiliently movable by the use of interconnected inflatable balls positioned under the pedals. As with Piaget et al., the Hsieh device may possibly be used, with some difficulty, from a seated position, but it is not conveniently designed for such use.
U.S. Pat. No. 5,299,995--Ko discloses a relatively small scale foot or leg exercising device in which a pair of conventionally pivoted bicycle pedals are mounted on flexible members that provide for a reciprocable movement in an adjustably pivoting tower arrangement which allows the user to, in effect, obtain a bicycling exercise motion from a seated position. The essential movement of the pedals is up and down on the apparatus.
There is a need for a small, easily portable and readily usable apparatus for mildly exercising the lower extremities, and particularly the feet and calves, from a sitting position such as is customarily assumed when watching television, operating a computer, traveling in a car or plane which will keep the legs and feet moving, but will not injure already injured muscles or ligaments. There is also a need for a method for use of this and similar apparatus to exercise the lower extremities.